Camera Module with Processor-Based MEMS-Actuated Autofocus

ABSTRACT

A miniature MEMS autofocus camera module includes an image sensor and an optical assembly including a movable lens group that comprises one or more lenses and that is coupled to a MEMS actuator such that the movable lens group is movable relative to the image sensor. The optical assembly further includes at least a first fixed lens group that comprises one or more lenses and that is fixed relative to the image sensor. A processor is programmed to control an autofocus method designed to adjust a focus distance to an object disposed an arbitrary distance from the miniature MEMS autofocus camera module by actuating the MEMS actuator that is coupled with the movable lens group.

PRIORITY

This application claims the benefit of priority to U.S. provisionalpatent application Ser. Nos. 61/609,293, filed Mar. 10, 2012 (Docket:IO2-0382-US-01); and 61/643,331, filed May 6, 2012 (Docket:IO2-0382-US-02), which are incorporated by reference.

This application is one of a group of related, contemporaneously-filedpatent applications by the same Assignee and Inventors, entitled:MINIATURE CAMERA MODULE WITH MEMS-ACTUATED AUTOFOCUS (Docket:IO2-0382-US-03); MINIATURE MEMS AUTOFOCUS ZOOM CAMERA MODULE (Docket:IO2-0382-US-04); CAMERA MODULE WITH MEMS AUTOFOCUS AND ZOOM (Docket:IO2-0382-US-05); MEMS AUTOFOCUS CAMERA MODULE WITH ALIGNMENTREGISTRATION (Docket: IO2-0382-US-06); CAMERA MODULE WITHPROCESSOR-BASED MEMS-ACTUATED AUTOFOCUS (Docket: IO2-0382-US-07); MEMSAUTOFOCUS CAMERA MODULE WITH MULTIPLE LENS GROUPS (Docket:IO2-0382-US-08); MEMS AUTOFOCUS CAMERA MODULE WITH FIXED AND MOVABLELENS GROUPS (Docket: IO2-0382-US-09), which are incorporated byreference.

BACKGROUND

1. Field of the Invention

The present application is related to electronic cameras and moreparticularly, to electronic cameras with autofocus and/or zoom, andparticularly having optical and electrical integration of autofocusand/or zoom components.

2. Description of the Related Art

If the position of an optical train of a camera is fixed relative to theposition of the image sensor, the resulting electronic camera is said tobe fixed focus. Rigidly fixing the optical system in place means onlyobjects that are a certain distance from the camera will be in focus onthe image sensor. Fixed focus cameras have advantages in terms ofsmallness of physical dimensions and cost, but the performance islimited. In particular, the focus distance is often set at 1.2 m so thatobjects from 60 cm to infinity appear tolerably sharp. However, theimage sharpness is not especially good and objects that are closer tothe camera than 60 cm will be blurred.

While it is possible to set the focus at a closer distance to correctfor this problem, this means that the sharpness of distant objectsdeclines in compensation. A characteristic that is common to bothconventional fixed and auto focus cameras is that the area that can beviewed, known as the field of view of the camera, is determined by theoptical design and the dimensions of the image sensor and cannot bechanged. For convenience, field of view is often described as theequivalent solid angle in the horizontal, vertical or diagonal plane.

Cropping an image to reduce the field of view has advantages that itentails no moving parts, can be performed almost instantaneously andinvolves very low power and physical space to implement. It is arelatively low cost method of changing the field of view. Howevercropping involves the loss of information. That is, to restrict thefield of view, an image is cropped to, say, one quarter of its originalarea, such that three quarters of the image is discarded. Consequently,a cropped image can often have inferior quality to both the originalimage and a mechanical zoom image of the same field of view.

Generally, the lower the quality of the optical train, the larger thePSF or point spread function will be. In many conventional cameras, theoptical train tends to be underspecified, such that points of capturedlight spread excessively to cover several pixels resulting in blurredimages.

Lenses may be assembled in a lens turret to form an optical train. In aconventional method, a lens turret may be fabricated first, after whichthe lenses may be inserted, and then fixed in a desired location insidethe lens turret. Methods of enhanced precision are desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates schematically certain components of an optical trainof an auto focus zoom camera in accordance with embodiments, includingfixed and moving lens groups for imaging a scene onto an image sensor.

FIGS. 2A-2B illustrate center and tilt misalignments, respectively,between the fixed and moving lens groups of an auto focus zoom camera inaccordance with certain embodiments.

FIGS. 3A-3B illustrate camera module guide pins in accordance withcertain embodiments, shown in section and plan view (inset).

FIGS. 4A-4B illustrate a circular sleeve in accordance with embodimentsin section and plan views.

FIGS. 4C-4G illustrate a selection of sleeves for guide pins that may beused in certain embodiments.

FIG. 5 illustrates an auto focus zoom camera module in accordance withembodiments including a moving lens mounted in a housing and the housingattached to sleeves that ride on guide pins.

FIG. 6 depicts a detail view of an example of an optical train inaccordance with embodiments where the fixed and moving lenses can bebeen aligned to each other by physical features.

FIG. 7 illustrates an auto focus zoom camera module at intermediatestate of assembly where the fixed and moving lenses are aligned byregistration features, but the housing of the moving lenses is notattached to the sleeves.

FIG. 8 illustrates a cross-section of a completed camera where a housingthat is offset to the optical axis has been joined to the sleeves withthe fixed and moving lenses still aligned to each other but separated bya working distance.

FIG. 9 depicts a plan view of an auto focus zoom camera where themechanical axis of the guide pins is offset from the optical axis.

FIG. 10A illustrates optics for a fixed focus camera.

FIG. 10B illustrates optics for an auto-focus camera.

FIG. 10C illustrates an example of an optical train for an autofocuszoom camera in accordance with embodiments.

FIG. 11 illustrates a section view of a camera module in accordance withcertain embodiments.

FIG. 12 illustrates a side view of the camera module of FIG. 11.

FIG. 13 illustrates the side view of the camera module of FIG. 12without the lenses.

FIG. 14 illustrates a top view of the camera module of FIGS. 11-13.

FIGS. 15-18 illustrate advantageous examples involving zoom factors forcamera modules in accordance with embodiments.

DETAILED DESCRIPTIONS OF THE EMBODIMENTS

A miniature MEMS autofocus camera module is provided that includes aMEMS actuated movable lens group and at least one fixed lens groupdefining an optical axis within a camera module housing within whichobjects disposed an arbitrary distance from the camera module areautomatically focused at a determined zoom to an image sensor by MEMSactuation of the movable lens group to accomplish autofocusfunctionality.

The camera module may include a processor and embedded code forprogramming the processor to electronically zoom the image data. Theelectronic zoom may utilize both electronic and optical processingelements. The optical autofocus may also utilize both electronic andoptical processing elements. One or more lenses may participate as asame electronic and optical processing element used for both the opticalautofocus and the electronic zoom.

The at least one fixed lens group may include first and second lensgroups. The movable lens group may be disposed between the first andsecond fixed lens groups.

An optical assembly for a miniature MEMS autofocus camera module is alsoprovided including a MEMS actuated movable lens group and at least onefixed lens group defining an optical axis within a housing configured tocouple with an image sensor component to capture digital images ofobjects disposed an arbitrary distance from the camera module that areautomatically focused at a determined zoom to an image sensor portion ofthe image sensor component by MEMS actuation of the movable lens groupto accomplish autofocus functionality.

The optical assembly may include contact pads for coupling with aprocessor programmed to electronically zoom the image data. Theelectronic zoom may utilize both electronic and optical processingelements. The optical autofocus may also utilize both electronic andoptical processing elements. One or more lenses may participate as asame electronic and optical processing element used for both the opticalautofocus and the electronic zoom.

The at least one fixed lens group may include first and second lensgroups. The movable lens group may be disposed between the first andsecond fixed lens groups.

An autofocus zoom miniature MEMS camera module is provided that includesa housing with an aperture for capturing digital images, an image sensorand an optical assembly. The optical assembly is provided with at leastone fixed lens group and at least one movable lens group. A MEMSactuator is configured to move the movable lens group along an opticalaxis of the camera module relative to the image sensor and the fixedlens group to automatically focus an object at a determined zoomdisposed an arbitrary distance from the camera module onto the imagesensor.

The movable lens group may include one or more movable lenses disposednearest an object end of the optical path that are movable along theoptical axis of the camera. The fixed lens group may include one or morefixed lenses disposed between the movable lens group and the imagesensor that are fixed in position relative to the image sensor, housingor a substrate to which the image sensor is coupled, or combinationsthereof.

The image sensor may be disposed approximately at a back focal length ofthe one or more fixed lenses. The one or more fixed lenses may beconfigured to compensate for a field curvature induced by the one ormore moving lenses. The one or more fixed lenses may be configured tomatch an associated point spread function to a pixel dimension of theimage sensor approximately uniformly over an area of the image sensor.The one or more fixed and movable lenses may be configured such that anautofocus distance range comprises 10 cm to 9 m. The one or more fixedand movable lenses may be configured such that an autofocus distancerange comprises 15 cm to 5 m. The one or more fixed and movable lensesmay be configured such that an autofocus distance range comprises 20 cmto 3 m. The autofocus distance may exclude a hyperfocal distance.

An optical assembly for an autofocus zoom miniature MEMS camera moduleis also provided that includes a housing defining an aperture, one ormore lenses that are fixed relative to the housing, a MEMS actuator, andone or more movable optical elements coupled to the MEMS actuator. Anobject disposed an arbitrary distance from a camera module that includesthe optical assembly is automatically focused at a determined zoom ontothe image sensor by MEMS actuation of the one or more movable opticalelements.

The optical assembly and/or MEMS camera module may include a zoomfeature ranging between ×0.5 and ×5, or between ×1 and ×3.

The optical assembly may include a movable lens housing containing theone or more movable lenses.

An optical axis of the one or more movable optical elements may bedisplaced from an optical axis of the camera module by not more thanapproximately 0.5 mm, or by not more than approximately 0.2 mm, or bynot more than approximately 0.1 mm.

The movable and fixed lens groups may be relatively disposed with acentering alignment within 90 microns, or in a range between 40 micronsand 140 microns.

A third lens group may be fixed relative to the housing. The movablelens group may be disposed between the first and third fixed lensgroups.

The focus travel length of the second lens group may be more than 50,100, 200, or 300 microns, and/or within a range between 100 microns and300 microns or within a range between 50 microns and 500 microns.

Another autofocus zoom miniature MEMS camera module is provided thatincludes a housing, a MEMS actuator, one or more movable opticalelements coupled to the MEMS actuator, an image sensor, a processor, anda storage medium having code embedded therein for programming theprocessor to perform an autofocus zoom method. An object disposed anarbitrary distance from the camera module is automatically focused at adetermined zoom onto the image sensor by MEMS actuation of the one ormore movable optical elements.

The code may be configured to program the processor to correct fordistortion or another artifact produced in a predictable manner by oneor more optical elements of the camera. The code may be configured toprogram the processor to process information from image sensor pixelsirrespective of a number of pixels within an image area that areilluminated by the one or more optical elements.

The code may be implemented in hardware or software or both.

The processor may be configured to perform an autofocus zoom methodwithin an image processing pipeline on the image sensor.

The processor may be configured to perform the autofocus zoom method ona discrete platform. The discrete platform may include an imageprocessor or image signal processor. The discrete platform may include abaseband chip in a mobile phone. A machine readable file that haslargely constant size and effective image resolution irrespective ofautofocus zoom setting.

The camera may be configured with a zoom feature ranging between ×0.5and ×5, or between ×1 and ×4, or between ×1 and ×3.

A movable lens housing may contain the one or more movable lenses. Themovable lens housing may be configured to be movable mechanically alongthe optical axis of the camera. The MEMS actuator or another actuatormay be configured to move the movable lens housing along the opticalaxis. The movable lens housing may include one or more guide pins andone or more sleeves configured such that the guide pins are fixed inposition while the sleeves move along the guide pins.

The guide pins may be mechanically referenced to the image sensor andthe sleeves may be joined to the movable lens housing. The guide pinsmay include two or more guide pins, or three or more guide pins, or fiveor more guide pins. The guide pins may include a circular cross section.The one or more sleeves may include a shape, when viewed in section,that forms one or more area contacts to the guide pins. The shape of theone or more sleeves may include an oval shape, a “V” shape, a triangularshape, a square shape, a pentagon shape, a hexagon shape, and/or anotherpolygon shape, e.g., a regular polygon, or an irregular polygon, or theone or more sleeves may have a circular shape.

The one or more sleeves may be configured to be forced into contact withthe one or more guide pins by a lateral force. The lateral force mayinclude approximately 0.5 grams. A spring may be used to provide thelateral force. A magnet may be used to provide the lateral force.

A movable housing may include one or more guide pins and one or moreflexible components that are flexible in a direction along the opticalaxis. The guide pins may be fixed in position while the flexiblecomponents move along the guide pins. The one or more flexiblecomponents may include leaf springs that are fixedly attached to theguide pins and the movable lens housing. The one or more flexiblecomponents may include one or more opposing pairs having a spring ratethat is approximately constant through a flexure range.

The camera module housing and image sensor may define an optical axis ofthe MEMS camera module. An axis of the one or more movable opticalelements may be displaced from the optical axis of the MEMS cameramodule by not more than approximately 0.5 mm, or by not more thanapproximately 0.2 mm, or by not more than approximately 0.1 mm.

The MEMS actuator may be configured to move the one or more movablelenses within a range between 50 and 500 microns, or within a 350 micronrange, or within a 200 micron range.

A method of assembly of a miniature MEMS camera module is provided. Themethod includes abutting registration features of an optical assemblythat includes both a fixed lens group and a movable lens group includingone or more movable lenses, and affixing the movable lens group inlocation within a movable lens housing. A MEMS actuator is coupled tothe movable lens group or housing or both, whereby in use the MEMSactuator is configured to move the movable lens group relative to thefixed lens group to automatically adjust a focus distance of the opticalassembly.

The affixing may involve applying an adhesive. The applying an adhesivemay include joining the movable lens housing to a sleeve that isconfigured to couple with a pin that is fixed to the miniature cameramodule.

The method may include coupling the optical assembly with an imagesensor component, which may involve fixing the fixed lens group relativeto an image sensor portion of the image sensor component while themovable lens group or movable lens housing or both is configured to bemovable relative to the image sensor portion by actuation of the MEMSactuator to adjust said focus distance of the optical assembly. Themethod may further include coupling the image sensor component to aprinted circuit.

The miniature MEMS camera module, upon assembly, may defines an opticalaxis that is displaced from an axis of the movable lens group not morethan approximately 0.5 mm, or not more than approximately 0.2 mm, or notmore than approximately 0.1 mm.

A miniature MEMS autofocus camera module is also provided that includesa housing, an image sensor coupled to the housing, an autofocus opticalmodule coupled within the housing and including a MEMS actuator that isconfigured to move one or more movable lenses relative to one or morefixed lenses along an optical axis of the camera module to adjust afocusing distance of the autofocus optical module to automatically focusan object disposed an arbitrary distance from the camera module onto theimage sensor. This miniature MEMS autofocus optical module includes oneor more pairs of adjacent lens surfaces that include abuttingregistration features to aid in alignment. An optical assembly for theaforementioned miniature MEMS autofocus camera module is also provided.

The one or more movable lenses may be disposed nearest an object end ofthe optical path between a housing aperture and the image sensor. Theone or more fixed lenses may include at least a first fixed lensdisposed between the one or more movable lenses and the image sensor.The image sensor may be disposed approximately at a back focal length ofthe first fixed lens.

The one or more fixed lenses may include at least a second fixed lensdisposed between the object end and the one or more movable lenses, suchthat the one or more movable lenses are disposed between the first andsecond fixed lenses. The second fixed lens may be configured inaccordance with a processor-implemented zoom component to apply zoom tocaptured image data.

The miniature MEMS camera module, upon assembly, may define an opticalaxis that is displaced from an axis of the movable lens group not morethan approximately 0.5 mm, or not more than approximately 0.2 mm, or notmore than approximately 0.1 mm. The one or more fixed lenses may includefirst and second fixed lens groups each comprising one or more lensesthat are fixed relative to the image sensor. The one or more movablelenses may be disposed between the first and second fixed lens groups.

A miniature MEMS autofocus camera module is also provided that includesan image sensor and an optical assembly including a movable lens groupthat includes one or more lenses and that is coupled to a MEMS actuatorsuch that the movable lens group is movable relative to the imagesensor. The optical assembly also includes at least a first fixed lensgroup that comprises one or more lenses and that is fixed relative tothe image sensor. A processor is programmed to control an autofocusmethod designed to adjust a focus distance to an object disposed anarbitrary distance from the miniature MEMS autofocus camera module byactuating the MEMS actuator that is coupled with the movable lens group.

The optical assembly may include a second fixed lens group that includesone or more lenses that are fixed relative to the image sensor. Themovable lens group may be disposed between the first and second fixedlens groups.

A first surface of the one or more fixed lenses furthest from the imagesensor and a second surface of the one or more movable lenses nearest tothe image sensor may be provided with one or more physical registrationfeatures configured to abut to aid alignment during assembly.

A spacer may be disposed between the first and second surfaces. Thespacer may have been inserted for operation after assembly. The absenceof the spacer during assembly may have permitted the registrationfeatures of the first and second surfaces to abut. The spacer may beconfigured to achieve a separation in a range between 50 and 500microns, or in a range between 50 and 150 microns, or in a range between200 and 300 microns, or the spacer may be configured to achieve aseparation of approximately 100 microns, or approximately 250 microns.

The optical assembly may include one or more pairs of adjacent lenssurfaces that include abutting registration features.

The miniature MEMS camera module, upon assembly, may define an opticalaxis that is displaced from an axis of the movable lens group not morethan approximately 0.5 mm, or not more than approximately 0.2 mm, or notmore than approximately 0.1 mm.

In operation of the autofocus zoom module, a registration of de-centerbetween the one or more fixed lenses and the one or more moving lensesmay be approximately seven microns or less, or approximately fivemicrons or less, or approximately three microns or less.

In operation of the autofocus zoom module, a registration of tiltbetween the one or more fixed lenses and the one or more moving lensesmay be approximately 0.3 microns or less, or approximately 0.2 micronsor less, or approximately 0.1 microns or less.

An optical assembly for a miniature MEMS camera module may include anoptical assembly housing, configured for coupling with an image sensorcomponent, and an autofocus optical module coupled within the housing.The autofocus optical module includes a MEMS actuator that is configuredto move one or more movable lenses relative to one or more fixed lensesalong an optical axis to adjust a focusing distance of the autofocusoptical module.

The one or more movable lenses may be disposed nearest an object end ofthe optical path and may be movable along the optical axis. The one ormore fixed lenses may be disposed nearest an image end of the opticalpath and may be fixed in position relative to the housing. The opticalassembly housing may be configured to couple with an image sensorportion of the image sensor component that is disposed approximately ata back focal length of the one or more fixed lenses.

The one or more fixed lenses may include first and second fixed lensgroups each having one or more lenses that are fixed relative to thehousing. The one or more movable lenses may be disposed between thefirst and second fixed lens groups. The optical assembly may include oneor more pairs of adjacent lens surfaces that include abuttingregistration features. The optical assembly, upon assembly with an imagesensor component, may define an optical axis that is displaced from anaxis of the movable lens group not more than approximately 0.5 mm, ornot more than approximately 0.2 mm, or not more than approximately 0.1mm.

The optical assembly and an image sensor component may be coupled toform an autofocus camera module, whereby a registration of de-centerbetween the one or more fixed lenses and the one or more moving lensescomprises approximately seven microns or less, or approximately fivemicrons or less, or approximately three microns or less.

A registration of tilt between the one or more fixed lenses and the oneor more moving lenses of the optical assembly may comprise approximately0.3 microns or less, or approximately 0.2 microns or less, orapproximately 0.1 microns or less.

A further miniature MEMS autofocus camera module is provided thatincludes an image sensor and an optical assembly including a movablelens group that includes one or more lenses and that is coupled to aMEMS actuator such that the movable lens group is movable relative tothe image sensor. The optical assembly further includes at least a firstfixed lens group that includes one or more lenses and that is fixedrelative to the image sensor. In operation of the miniature MEMSautofocus camera module, a registration of de-center between the one ormore fixed lenses and the one or more moving lenses comprisesapproximately seven microns or less.

A first surface of a first fixed lens of the first fixed lens group anda second surface of a first movable lens of the movable lens group maybe provided with one or more physical registration features configuredto abut to aid alignment.

A first surface of the one or more fixed lenses furthest from the imagesensor and a second surface of the one or more movable lenses nearest tothe image sensor may be provided with one or more physical registrationfeatures configured to abut to aid alignment.

In operation of the autofocus zoom module, a registration of de-centerbetween the one or more fixed lenses and the one or more moving lensesmay comprise approximately five microns or less, or approximately threemicrons or less.

In operation of the autofocus zoom module, a registration of tiltbetween the one or more fixed lenses and the one or more moving lensescomprises approximately 0.3 microns or less, or approximately 0.2microns or less, or approximately 0.1 microns or less.

A spacer may be disposed between the first and second surfaces. Thespacer may have been inserted for operation after assembly. The absenceof the spacer during assembly may have permitted the registrationfeatures of the first and second surfaces to abut. The spacer may beconfigured to achieve a separation in a range between 50 and 500microns, or in a range between 50 and 150 microns, or in a range between200 and 300 microns, or the spacer may be configured to achieve aseparation of approximately 100 microns, or approximately 250 microns.

Another miniature MEMS-actuated camera module is provided that includesone or both of a camera module housing or a rigid substrate that eitherdefines an aperture or is coupled to an aperture, or both. An imagesensor is coupled to the one or both of the camera module housing orrigid substrate. A first lens group is coupled to the housing and fixedrelative to the image sensor or coupled directly to the image sensor orboth. A MEMS actuator is coupled to the housing or rigid substrate. Asecond lens group is coupled to the actuator and is movable relative tothe image sensor.

An optical assembly for the miniature MEMS camera module may include ahousing that either defines an aperture or is coupled to an aperture, orboth, and that is configured to couple with an image sensor componentfor focusing images with said optical assembly onto an image sensorportion of said image sensor component when said housing is coupled tosaid image sensor component, a first lens group coupled to and fixedrelative to the housing, a MEMS actuator coupled to the housing, and asecond lens group coupled to and movable with the MEMS actuator relativeto the first lens group.

A rigid substrate may be coupled to the camera module housing.

A lens barrel may contain at least the second lens group.

The MEMS actuator may be coupled to one, two, three, four or more lensesof the second lens group for moving the one, two, three, four or morelenses along the optical path relative to the image sensor.

The second lens group may include four lenses. The first lens group mayinclude a single lens.

The second lens group may include a single movable lens. The first lensgroup may include two fixed lenses. A third lens group may include oneor two more fixed lenses. The second lens group may be disposed andmovable through an autofocus range between the first and third fixedlens groups.

The first and second lens groups may be relatively disposed with acentering alignment within 1 micron, or within 3 microns, or within 5microns, or within 10 microns.

The first and second lens groups may be relatively disposed with a tiltalignment within of 0.01°, or within 0.05°, or within 0.1°, or within0.2°, or within 0.3°, or within 0.4°.

The first and second lens groups may be relatively disposed within acentering alignment in a range between of 1 micron and 10 microns, or ina range between 2 microns and 5 microns.

The first and second lens groups may be relatively disposed within atilt alignment in a range between 0.05° and 0.3°, or in a range between0.1° and 0.2°.

The focus travel length of the second lens group may be more than 50microns, or more than 100 microns, or more than 150 microns, or morethan 200 microns, or more than 250 microns, or more than 300 microns, orwithin a range between 100 microns and 300 microns, or within a rangebetween 50 microns and 500 microns.

The first lens may be disposed a distance from the sensor along theoptical path within a range between around its back focal length±10microns. The back focal length may include between 700 and 1100 microns,or between 500 and 1300 microns, or approximately 900 microns.

The second lens group and image sensor may be relatively disposed with acentering alignment within 90 microns, or in a range between 40 micronsand 140 microns.

A third lens group may be coupled to the housing and fixed relative tothe image sensor. The second lens group which is movable relative to theimage sensor may be disposed between the first and third lens groupswhich are each fixed relative to the image sensor.

A camera in accordance with embodiments described herein includes animage sensor, which converts an image in an optical domain to anelectronic format, and an optical train that focuses the scene ofinterest onto the image sensor. Embodiments include cameras configuredwith an enhanced ability to accurately capture detail in a scene. Thequality of the optical train and/or the resolution of the image sensormay be selected in accordance with a desired ability to accuratelycapture such detail. The image sensor may contain millions of pixels(picture elements) and the optical train may include two, three, four,five or more lenses.

The position of at least one movable lens of the optical train is notfixed relative to the position of the image sensor, and thus, cameras inaccordance with embodiments described herein can alter the distance fromthe electronic camera at which objects will be in focus on the imagesensor. A system may be utilized in accordance with certain embodimentsto determine one or more distances of one or more principal objects in ascene from the camera. The at least one movable lens is movable inaccordance with the determined distance in certain embodiments and/oruntil one or more principle objects are in focus on the image sensor.These objects can range from being very close (10 cm or closer) to verydistant (infinity) from the camera.

Embodiments are provided herein of cameras that provide image qualitythat is better than conventional autofocus and fixed focus cameras.Cameras in accordance with certain embodiments also exhibit miniaturesize, as well as advantageous power efficiency.

Electronic cameras in accordance with certain embodiments exhibit anadvantageous capability to alter the field of view significantly. Forexample, a photograph of a family taken in front of their house mightinadvertently include a refuse container at the edge of the scene when aconventional camera is being used. A camera in accordance with certainembodiments can be adjusted to restrict the field of view of the camerato eliminate this artifact from the captured image. Conversely, aphotograph of a family taken on top of a hill can be enhanced using acamera in accordance with certain embodiments by adjusting to a widerfield of view that captures more of the panorama.

It is possible to alter the field of view of an electronic camera inaccordance with certain embodiments in multiple ways. One way is toalter an aspect of the optical system, e.g., using zoom capability,whereby one or two or more and in some embodiments four or more lenses,and/or one or more apertures, is/are movable back and forth along theoptical axis of the camera.

Another way of changing the field of view of an electronic camera inaccordance with certain embodiments is to crop, delete and/or clipperipheral regions of the captured scene when it is in electronicformat, although cropping is subject to the limitations described aboveinvolving the discarding of peripheral image data. However, because acropped image is smaller than the original, it can be electronicallyexpanded so that it is the equivalent size as the original but, becauseparts of the scene are now absent, the effective field of view isdiminished.

Another method of accomplishing zoom in an electronic camera inaccordance with certain embodiments exploits matching the so-calledpoint spread function of the optical train to the image sensor. Pointspread function (PSF) can be defined as a quantity that describes theextent to which a theoretical point of light of zero area would expandas it passes through the optical train of the camera and/or would spreadout by viewing, optical quality, diffraction, following up on accuracy,and/or the resolution of the sensor. The expansion occurs due to defectsin the materials used for the lenses, surface imperfections, alignmenttolerances and/or potentially a host of other factors. A good matchbetween the optical train and image sensor occurs when the PSF matchesthe dimensions of the pixels in the image sensor. If the optical trainis over-specified, the point of light will spread slightly and remainsmaller than one pixel.

In certain embodiments, the PSF of the optical train does not varysignificantly with the radius. This electronic camera has no significantmismatch between the PSF and pixel size across the lens radius. In someembodiments, the pixels in the center are smaller than those at theperiphery to match the variation in PSF function across the lens radius.

In certain embodiments, the PSF is set to match the pixel size at abouttwo thirds of the lens radius, particularly when it is determined thatthe objects of greatest interest in the scene are in the center of theimage.

In an alternative embodiment, an optical train is designed so that atthe periphery the PSF matches the pixel size of the imager. This opticdesign is adjusted as it is continued inwards, so that it results in thelens being over-specified since the PSF decreases towards the opticalaxis. In certain embodiments, the magnification of the optical system isincreased towards the center. This magnification increases the effectivesize of the point of light and hence the effective PSF. Themagnification may be set to be sufficient so that the PSF matches thepixel size over the entire area of the imager. The result is the lenshas higher magnification in the center than at the periphery.

An electronic camera using an optic of the type described is able toprovide for dynamic alteration of the field of view, in other wordszoom, by imaging cropping. The resolution of the cropped imageadvantageously does not diminish since the center of the image has beenmagnified by the lens. The special optic involved in producing a dynamicfield of view camera in accordance with certain embodiments generallyproduces distortion of the image that resembles barrel distortion. Theextent of the distortion is fixed and controlled by the lens design. Incertain embodiments, this distortion is corrected and removed, alongwith potentially one or more other predictable artifacts, using anadvantageous image processing technique incorporated in a camera systemin accordance with certain embodiments that has code embedded within adigital storage device for programming a camera processor to perform thetechnique and generate modified image data.

Cameras in accordance with certain embodiments exhibit clearimprovements in overall performance by incorporating dynamic field ofview feature with an auto focus mechanism. In certain embodiments, thedesign of the optical train of the camera includes a part that is fixedand a part that is movable along the optical axis of the camera by anactuator. In certain embodiments, some image processing is provided bycode embedded within a fixed or removable storage device on the cameraand/or using a remote processor, e.g., removal of image distortion.

Advantageous cameras are provided in accordance with certain embodimentsthat integrating all three of these in a compact camera module. Suchcamera module may be a stand-alone camera product, or may be included ina fixed or portable electronics product, and/or in various otherenvironments such as automobiles.

Several embodiments will now be described with reference to the figures.Electronic cameras are provided herein that advantageously incorporateintegrated auto focus and zoom functionality. In certain embodiments,the autofocus and zoom functions utilize a combination of anadvantageous optical train and processor-based image processing, and incertain embodiments include the same or similar components in bothcases.

An optical train in accordance with certain embodiments that is able torealize the desired functions of auto focus and zoom includes twogeneral components (see FIG. 1). These are a first lens group 101 of oneor more lenses that can be moved 102 along the optical axis 103 of thecamera (hereafter referred to as the “moving lens”) and a second lensgroup 104 of one or more lenses that are fixed in position (hereafterreferred to as the “fixed lens”). The moving lens is the lens closest toscene 105 and the fixed lens is the lens closest to the imager 106. Ingeneral terms, the moving lens performs the function of altering thefocal distance of the camera and the fixed lens performs the function ofmatching the PSF function of the optic to the imager and compensatingfor the field curvature induced by the moving lens.

The moving lens is located at an appropriate distance along the opticalaxis to achieve the desired focus distance, while the fixed lens islocated such that its back focal length matches the distance between thelens and the imager.

A processor programmed by embedded code collects information from pixelsin the image sensor and makes changes to the associated electronic file,in some cases automatically and in others based on user inputs. Forexample, the degree of zoom is adjustable. The processor endeavors tocorrect for distortion and other artifacts that are produced in apredictable manner by the optical train. The image processing featurescan be implemented in either hardware or software. In certainembodiments, these features are placed early in the image processingpipeline, such as RTL (resistor transistor logic) code embedded in theimage sensor, while in others they are placed on an external DSP(digital signal processor) or entirely in software in a processor, suchas the base band chip in a mobile phone.

The resulting auto focus zoom camera example illustrated at FIG. 1 has afocus distance that can range 1 Ocm to 9 m, is typically 15 cm to 5 mand is preferably 20 cm to 3 m (excluding the hyper-focal distance),while the zoom function can range ×0.5-×5, is typically ×1-×4 and ispreferably ×1-×3. A noteworthy characteristic of the final electronicfile produced by the advantageous camera illustrated schematically atFIG. 1 is that file size and effective resolution of the image containedwithin it may be largely constant in certain embodiments irrespective ofthe focus distance and zoom setting.

In contrast to traditional electronic cameras that are either fixedfocus, where no lenses move, or auto focus where the entire opticaltrain is moved, advantageous cameras in accordance with embodimentsdescribed herein include optical trains with both a movable componentand a fixed component. These advantageous auto focus zoom cameras haveone or more parts of the optical train fixed and one or more partsmoving. In certain embodiments, cameras exhibit exactitude of centeringand tilt alignment of the moving lens to the fixed lens that differsfrom conventional fixed or auto focus cameras.

With reference to the example illustrated schematically at FIG. 2: Theregistration of de-center between the fixed and moving lens can range+/−7 um, is typically +/−5 um and is preferably +/−3 um. When theoptical axis 201 of the camera and the fixed lens 202 is not co-incidentwith the optical axis 203 of the moving lens 204, de-center 205 results.The registration of tilt is between the fixed and moving lens can range+/−0.3 um, is typically +/−0.2 um and is preferably +/−0.1 um. When theoptical axis optical axis 203 of the moving lens 204 is tilted withrespect to the optical axis 201 of the camera and the fixed lens 202,tilt 206 results.

The above features may be advantageously achieved when cameras inaccordance with certain embodiments are first assembled and then aresustained when the camera is operated, in particular when the movinglens is intentionally displaced along the optical axis of the camera.How these criteria are met during assembly and operation of the cameraare two further advantageous features of cameras in accordance withembodiments described herein.

Cameras in accordance with certain embodiments are configured to performregistration between the moving lens and the optical axis of the cameramodule during operation. With reference to FIG. 3, a camera module 301is provided with one or more guide pins 302 that run parallel to theoptical axis 303. The optical axis is determined by a line 305 drawnnormal to the center of the imager 306. The guide pins can number up to5 or more, and may be typically 2 or 3 in certain embodiments, while inanother embodiment, one guide pin is used in combination with a secondstabilization and alignment component. The one or more guide pins may becircular in cross-section, or alternatively may be elliptically-shaped,or may have be a regular or irregular polygon of any number of three ormore sides.

In embodiments involving multiple (i.e., two or more) guide pins, theguide pins may be in some embodiments distributed in a substantiallyequidistant fashion about the image sensor, and in other embodiments,two guide pins are more closely spaced than a third guide pin, and inother embodiments, two guide pins are closer on one side than anotherwhile a second stabilization and alignment component is also used.

To provide motion substantially or approximately solely in a directionparallel to the optical axis, movable sleeves are placed over the guidepins in certain embodiments, as illustrated schematically in the exampleof FIG. 4. The sleeves can take many forms, some examples being shown inFIG. 4. However, because advantageous camera modules in accordance withcertain embodiments are configured to eliminate or significantly reducemechanical play, the sleeve makes physical contact with the guide pin ina consistent and predictable manner throughout the stroke of themoveable lens group.

In addition, miniature cameras in accordance with certain embodimentsare configured to minimize or significantly reduce friction forcebetween the sleeve and guide pin. This feature advantageously assiststhe miniature actuator that is used to move the movable lens group, suchthat the actuator can move the movable lens group with a smaller appliedmotive force than if greater friction were present.

Advantageous low surface friction materials, bearings and/or other lowfriction components may be used. Geometries of the sleeve that are usedin certain embodiments provide a small number of small area contactpoints to the guide pin. Examples include V-grooves, triangles, squares,pentagons, hexagons, ellipses and other regular and irregular curvedshapes and polygons. Of these, V-grooves provide the fewest, i.e., two.A V-groove in a solid object may be realized from two faces set at anobtuse angle, such as from two faces of a pentagon that is larger indiameter than the guide pin, or alternatively from two faces set at anacute angle although these acute angle embodiments have an overalllarger diameter than the obtuse angle embodiments.

In an example embodiment of a pentagon shape, in order to ensure thatthe same two faces of the pentagon are in contact with the guide pin, afurther embodiment includes a mechanism or other stabilization oralignment component that ensures a small lateral force is always presentbetween the pentagon and the guide pin. This force can typically rangebetween 0.1 gf and 5 gf (gram-force), and may be between 0.2 gf and 2 gfand may be approximately 0.5 gf in certain embodiments. Lateral forcesof this magnitude are advantageously developed in various embodimentsusing one or more springs, compressed materials (e.g., a block ofrubber), and/or magnets.

The moving lens in several embodiments includes a group of individuallenses, apertures and optionally other optical components, thesecomponents are mounted together as a unitary element within a housing.The housing in certain embodiments is attached to one or more sleevesthat couple with one or more guide pins. An example of one of theseembodiments is schematically illustrated in FIG. 5. The fixed lenses 501are connected to the camera module body 502, as is the imager 503. Theimager defines the optical axis of the camera 504. The moving lenses 505are located in a housing 506, which is joined by a medium 507 to asleeve 508. The sleeves are located on the guide pins 509. Methods ofmaking the joints between the housing and the sleeves, both of whichinclude in certain embodiments polymeric materials, may include adhesivebonding.

Various embodiments are provided that involve methods of displacing thehousing containing the moving lens group along the optical axis. Anactuator is used in certain embodiments that can include, but is notlimited to, devices that operate on principles of the piezo-electric,electro-magnetic, electro-thermal and electrostatic effects such as mayinvolve a (micro-electro-mechanical system) MEMS component. Of these, apiezo-electric actuator may be used that delivers relatively high force.Other actuators may be selected that deliver an extended range oftravel. The actuator is configured to deliver an approximately minimumforce to overcome the friction forces of the sleeves against the guidepins and lift the weight of the housing, the one or more lenses and/orother optical components that the movable lens housing contains, againstgravity.

The travel involved in many embodiments of the movable lens group in anauto focus zoom camera module is relatively small, e.g., in a rangebetween 50 and 500 microns and may be in a range around approximately350 microns or 200 microns In certain embodiments, an alternative tousing guide pins and sleeves to control the motion of the housing alongthe optical axis of the camera involves use of components that areflexible in a direction along the optical axis, but relatively stiff inone or more other directions.

A leaf spring is used in certain embodiments. This advantageous leafspring may include a strip of metal whose length is substantiallygreater than its width, which is in turn substantially greater than itsthickness. The dimensional ratios may be around 10:1 in each case, andthey are smaller or larger than this example ratio in severalembodiments. By fixing one end of a leaf spring to a guide pin and theother end to the housing in accordance with certain embodiments, motionis largely restricted to being along the optical axis of the camera. Inone embodiment, a total of four leaf springs are used, with two pairs onopposing sides of the camera housing. Where an even of leaf springs isused, a further embodiment involves half of the springs on each side toform an opposing pair. That is, extension of one spring results incompression in the other. This advantageous mechanical arrangementpermits high stiffness at a low effective spring rate. The highstiffness greatly decreases motion of the housing in undesireddirections while the low spring rate is advantageous when the cameramodule includes a miniature actuator that produces a relatively smallforce.

A miniature auto focus zoom camera that contains fixed and moving lensesin accordance with certain embodiments exhibits high image quality dueto a high accuracy with which the optical elements, notably the lenses,are manufactured and assembled as an optical train. These optics areadvantageously very close to the computed ideal design. One reason forthis is that the assembly presents reduced risk, due to the lenses beingplaced to very high precision in one or more degrees of freedom and incertain embodiments, in five degrees of freedom. In certain embodiments,even rotation is prohibited for lenses that are not symmetric about theoptical axis. Advantageous methods are used in assembling auto focuszoom cameras in accordance with certain embodiments, including highprecision assembly of pre-assembled fixed and moving lenses.

A method in accordance with certain embodiments involves provide one ormore lenses with one or more physical features that register withsignificant precision with an adjacent component such as the next lensin the optical train. Having accurately assembled the optical train, theoptical train is then inserted into a housing. An adhesive is thenapplied to hold the lens train in position in the housing.

This method is particularly advantageous when used to assemble fixed andmoving lenses and individual components, although adjustments forbuilding an auto focus zoom camera module are provided in certainembodiments. The adjustments are provided because there is a spacebetween the fixed and moving lens group in certain embodiments. Thisspace can range between 50 and 500 microns, and may be in a range aroundapproximately 250 microns in some embodiments, and in a range aroundapproximately 100 microns in other embodiments. In these embodiments,the lenses do not abut for the purposes of registration while also beingseparated for operation at the same time.

Embodiments therefore include structures and a method that are used toprovide accurate alignment between fixed and moving lenses that areseparated by a gap. The basis of these embodiments is to provideadjacent surfaces of the fixed lens and the moving lens with physicalregistration features. While mating cups and cones are provided asexamples of such features herein, various shapes and sizes of suitablealignment features may be used.

With reference to FIG. 6, the lower moving lens 601 has a cone 602 onits image side while the upper fixed lens 603 has a cup 604 on itsobject side. The cones and cups can be reversed so the cups are on theimage side and the cones are on the object side. The optical train canbe aligned by stacking of the lenses so the cups and cones nest. Thecups and cones provide significantly precise registration in plan androtation from the object side of the moving lens to the image side ofthe fixed lens. The pitch, yaw and vertical spacing between lenses isdictated by the precision with which the physical registration featuresabut. In FIG. 6, it is the lenses themselves that are depicted asdesigned abutting; however the abutting components between the fixed andmoving lenses may include additional components such as spacers.

At this juncture, with the fixed and moving lenses abutted, the opticaltrain is precisely aligned. FIG. 7 schematically illustrates anautofocus zoom camera module at this step of assembly. The housing 701has been deliberately drawn asymmetrically with respect to the opticalaxis, 702 to illustrate that it is the cup and cone registrationfeatures 703 that provide the alignment between the fixed 704 and movinglenses 705 at this juncture, not the housing and guide pins 706.Adhesive 707, or another joining method may be applied and activated incertain embodiments to attach the housing to the sleeves, or the leafsprings, as appropriate. Because the guide pins are parallel to theoptical axis, the housing may now be displaced (801) along the opticalaxis until the desired separation (802) between the fixed and movinglenses is obtained, without significantly altering the alignment betweenthe fixed and moving lenses. The resulting structure then appears asdrawn in FIG. 8.

Lenses may be assembled in alternative embodiments into a lens turret toform the optical train. In certain alternative embodiments, the lensturret may be fabricated with an accurate interior space, and the lensesof the movable group inserted and fixed in the desired location insidethe lens turret. In the preceding discussion and drawings it hasgenerally been presumed that mechanical components of an autofocuscamera, such as guide pins, sleeves and a housing in certainembodiments, are symmetric about the optical axis of the camera. Incertain embodiments this is desirable, while in others it is not.

An example of one or these embodiments is schematically illustrated atFIG. 9. The optical axis of the camera 901 is derived from the imager902. The mechanical axis 903 is derived from the guide pins 904 (fourguide pins are drawn to illustrate the central location). Because thecamera module of this embodiment includes an actuator 905, which takesspace, the mechanical axis is displaced 906 from the optical axis adistance that can range to 0.5 mm in some embodiments, or 0.2 mm inother embodiments, or 0.1 mm or smaller in further embodiments.

FIGS. 10A-10B illustrate differences between optics for a fixed focuscamera compared with an auto-focus camera. The fixed focus camera ofFIG. 10A has not moving lenses and instead includes five fixed lensesL1-L5. FIG. 10B illustrates an example of an auto-focus camera whereinfive lenses L1-L5 are movable together to adjust focus of an object atan arbitrary distance from the camera module onto the image sensor.Using a voice coil motor or VCM actuator, the five lenses L1-L5 aremovable to adjust the focus. As described above, a MEMS actuator isincluded in accordance with several embodiments to move one or moremovable lenses quickly and without adding nearly as significantly to a Zheight of the camera module or thickness along the optical path ordirection of motion of the movable lens or movable lenses.

FIG. 10C illustrates an example of an optical train for an autofocuszoom camera in accordance with embodiments. In the example of FIG. 10C,lenses L1-L4 that are nearest an object end of the optical path aremovable to achieve autofocus functionality, while L5 is fixed nearest tothe image sensor. In fact, lens L5 has a back focal length equal to itsdistance from the plane of the image sensor. As described above,electronic zoom may be provided by a combination of this fixed L5 lensand data processing. The lens L5 is designed to compensate for a bigfield curvature. The overall optical assembly may have fewer than fivelenses or more than five lenses. Moreover, the movable lens group mayinclude fewer than four lenses, and may include as few as one lens thatmay be disposed at position L1, L2, L3 or L4 when L5 is designed toprovide zoom functionality.

FIG. 11 illustrates a section view of a camera module in accordance withcertain embodiments. In the example of FIG. 11, L1-L4 are movable whileL5 is fixed nearest the image sensor. The movable lenses L1-L4 aredisposed in a movable lens housing that is coupled to a camera modulebody or image sensor component that is itself coupled to a flexibleprinted circuit. The movable lens housing utilizes a set of pairs ofguide pins and sleeves to facilitate the motion of the movable lensesL1-L4 as actuated by the MEMS, piezo, VCM or other actuator (not shownin FIG. 11).

FIG. 12 illustrates a side view of the camera module of FIG. 11. A piezomotor is indicated in the example of FIG. 12 for moving the movable lenshousing the sleeves and guide pins. Alternatively, a MEMS actuator maybe used to move one, two, three or four movable lenses to facilitate anautofocus feature or an autofocus zoom feature of an advantageous cameramodule. The de-center and tilt alignment of the movable lens group isadvantageously precise as described herein, while objects at arbitrarydistances from the camera module are automatically brought to focus bymovement of the movable lens or movable lenses of the autofocus cameramodule. An ASIC or other electronic component is illustrated in FIG. 12as also being coupled to the flexible printed circuit along with thecamera module.

FIG. 13 illustrates the side view of the camera module of FIG. 12without the lenses L1-L5. In the example wherein a piezo is used, amotor substrate is included as illustrated at FIGS. 12-13.

FIG. 14 illustrates a top view of the camera module of FIGS. 11-13. Twopairs of sleeves and guide pins are shown in this embodiment totranslate the movable lens housing containing the movable lens group ofthe optical train of the camera module relative to the image sensor andto the camera module housing and to one or more fixed lenses in certainembodiments. The camera module of FIG. 14 includes a piezo motor or MEMSfor moving the movable lens housing and/or one or more movable lenses ofthe optical train whether or not the lens barrel also itself is movable.In the embodiment wherein lenses L1 and L2 are fixed in a first fixedlens group and lenses L4 and L5 are fixed in a second fixed lens groupand only lens L3 is movable to facilitate autofocus, the movable lenshousing may itself by fixed while the MEMS component is coupled to thelens L3 and moves the lens L3 to adjust the focus distance to objectsdisposed at arbitrary distances to the camera module. A position sensormay be included for monitoring, tracking, sensing and/or determining aposition of the movable lens housing or of the one or more movablelenses of the optical train. An orientation sensor may also be includedin the form of an accelerometer or by utilizing capacitance values forMEMS positioning components as described in more detail separately.

FIGS. 15-18 illustrate advantageous examples involving zoom factors forcamera modules in accordance with embodiments. In certain embodiments,optical zoom (OZ) may be used to create zoom using a distorted lens andexcess amount of pixels in the sensor. The optical zoom factor may becalculated a product of lens distortion zoom and extra pixels zoom and adigital component. In one example wherein a five megapixel or 5 MPoutput is provided, then for a sensor having excess pixels up to 8 MP, azoom factor of 1.265 is achieved by the extra pixels. For excess pixelsup to 10, 12 or 14 MP, zoom factors of 1.414, 1.550 and 1.673 arerespectively achieved.

A zoom factor provided by an optical zoom lens depends on the allowedtotal track length (TTL) of the lens. For example, for a large TTL(e.g., around 7 mm), a zoom factor of 1.42 is achieved at center field,while for a smaller TTL (e.g., around 5.7 mm), a zoom factor of 1.32 isachieved at center field in certain embodiments. Continuing with theseexamples, if a 5 MP output is provided, and a 12 MP input sensor isavailable, then for low TTL, an overall zoom factor obtained by theoptical zoom system at center field is about ×2. For a larger lens andTTL of 7 mm, e.g., the optical zoom factor is about ×2.2. FIGS. 17-18respectively illustrate zoom factors for a 12 MP input sensor and an 8MP input sensor.

While example drawings and specific embodiments of the present inventionhave been described and illustrated, it is to be understood that thatthe scope of the present invention is not to be limited to theparticular embodiments discussed. Thus, the embodiments shall beregarded as illustrative rather than restrictive, and it should beunderstood that variations may be made in those embodiments by workersskilled in the arts without departing from the scope of the presentinvention. For example, camera modules in accordance with variousembodiments and component of camera modules are described at U.S. patentapplication Ser. Nos. 13/732,276, 13/571,393, 13/571,395, 13/571,397,13/571,405, 13/445,857, 61/643,331, 61/657,012, 61/675,812, 61/698,567,61/748,054, 61/748,062, 61/622,480.

In addition, in methods that may be performed according to preferredembodiments herein and that may have been described above, theoperations have been described in selected typographical sequences.However, the sequences have been selected and so ordered fortypographical convenience and are not intended to imply any particularorder for performing the operations, except for those where a particularorder may be expressly set forth or where those of ordinary skill in theart may deem a particular order to be necessary.

In addition, all references cited herein are incorporated by reference,as well as the background, abstract and brief description of thedrawings, and U.S. application Ser. Nos. 12/213,472, 12/225,591,12/289,339, 12/774,486, 13/026,936, 13/026,937, 13/036,938, 13/027,175,13/027,203, 13/027,219, 13/051,233, 13/163,648, 13/264,251, and PCTapplication WO2007/110097, and U.S. Pat. Nos. 6,873,358, and RE42,898are each incorporated by reference into the detailed description of theembodiments as disclosing alternative embodiments.

The following are also incorporated by reference as disclosingalternative embodiments:

U.S. Pat. Nos. 8,331,715, 8,279,301, 8,270,674, 8,224,108, 8,184,967,8,055,090, 8,055,029, 7,855,737, 7,995,804, 7,970,182, 7,916,897,8,081,254, 7,620,218, 7,995,855, 7,551,800, 7,515,740, 7,460,695,7,965,875, 7,403,643, 7,916,971, 7,853,043, 7,773,118, 8,055,067,7,844,076, 7,315,631, 7,792,335, 7,680,342, 7,692,696, 7,599,577,7,606,417, 7,747,596, 7,506,057, 7,685,341, 7,694,048, 7,715,597,7,565,030, 7,636,486, 7,639,888, 7,634,109, 7,536,036, 7,738,015,7,590,305, 7,362,368, 7,352,394, 7,564,994, 7,315,658, 7,630,006,7,440,593, 7,317,815;

U.S. patent application Ser. Nos. 13/306,568, 13/282,458, 13/234,149,13/234,146, 13/234,139, 13/220,612, 13/084,340, 13/078,971, 13/077,936,13/077,891, 13/035,907, 13/028,203, 13/020,805, 12/959,320, 12/944,701,and 12/944,662;

United States published patent applications serial nos. 20120019614,20120019613, 20120008002, 20110216156, 20110205381, 20120007942,20110141227, 20110002506, 20110102553, 20100329582, 20110007174,20100321537, 20110141226, 20100141787, 20110081052, 20100066822,20100026831, 20090303343, 20090238419, 20100272363, 20090189998,20090189997, 20090190803, 20090179999, 20090167893, 20090179998,20080309769, 20080266419, 20080220750, 20080219517, 20090196466,20090123063, 20080112599, 20090080713, 20090080797, 20090080796,20080219581, 20090115915, 20080309770, 20070296833, and 20070269108.

What is claimed is:
 1. A miniature MEMS autofocus camera module,comprising: an image sensor; an optical assembly including a movablelens group that comprises one or more lenses and that is coupled to aMEMS actuator such that the movable lens group is movable relative tothe image sensor, wherein the optical assembly further includes at leasta first fixed lens group that comprises one or more lenses and that isfixed relative to the image sensor; a processor; and a non-transitorydigital storage device having code embedded therein for programming theprocessor to control an autofocus method designed to adjust a focusdistance to an object disposed an arbitrary distance from the miniatureMEMS autofocus camera module by actuating the MEMS actuator that iscoupled with the movable lens group.
 2. The miniature MEMS autofocuscamera module of claim 1, further comprising a second fixed lens groupthat comprises one or more lenses and that is fixed relative to theimage sensor, wherein the movable lens group is disposed between thefirst and second fixed lens groups.
 3. The miniature MEMS autofocuscamera module of claim 1, wherein a first surface of the one or morefixed lenses furthest from the image sensor and a second surface of theone or more movable lenses nearest to the image sensor are provided withone or more physical registration features configured to abut to aidalignment during assembly.
 4. The miniature MEMS autofocus camera moduleof claim 1, whereby in operation of the autofocus zoom module, aregistration of de-center between the one or more fixed lenses and theone or more moving lenses comprises approximately seven microns or less.5. The miniature MEMS autofocus camera module of claim 1, whereby inoperation of the autofocus zoom module, a registration of de-centerbetween the one or more fixed lenses and the one or more moving lensescomprises approximately five microns or less.
 6. The miniature MEMSautofocus camera module of claim 1, whereby in operation of theautofocus zoom module, a registration of de-center between the one ormore fixed lenses and the one or more moving lenses comprisesapproximately three microns or less.
 7. The miniature MEMS autofocuscamera module of claim 1, whereby in operation of the autofocus zoommodule, a registration of tilt between the one or more fixed lenses andthe one or more moving lenses comprises approximately 0.3 microns orless.
 8. The miniature MEMS autofocus camera module of claim 1, wherebyin operation of the autofocus zoom module, a registration of tiltbetween the one or more fixed lenses and the one or more moving lensescomprises approximately 0.2 microns or less.
 9. The miniature MEMSautofocus camera module of claim 1, whereby in operation of theautofocus zoom module, a registration of tilt between the one or morefixed lenses and the one or more moving lenses comprises approximately0.1 microns or less.
 10. The miniature MEMS autofocus camera module ofclaim 1, further comprising a spacer between the first and secondsurfaces.
 11. The miniature MEMS autofocus camera module of claim 10,wherein the spacer has been inserted for operation after assembly, itsabsence during assembly having permitted the registration features ofthe first and second surfaces to abut.
 12. The miniature MEMS autofocuscamera module of claim 10, wherein the spacer is configured to achieve aseparation in a range between 50 and 500 microns.
 13. The miniature MEMSautofocus camera module of claim 10, wherein the spacer is configured toachieve a separation in a range between 50 and 150 microns.
 14. Theminiature MEMS autofocus camera module of claim 10, wherein the spaceris configured to achieve a separation in a range between 200 and 300microns.
 15. The miniature MEMS autofocus camera module of claim 10,wherein the spacer is configured to achieve a separation ofapproximately 100 microns.
 16. The miniature MEMS autofocus cameramodule of claim 10, wherein the spacer is configured to achieve aseparation of approximately 250 microns.
 17. The miniature MEMSautofocus camera module of claim 1, wherein the optical assemblycomprises one or more pairs of adjacent lens surfaces that includeabutting registration features.
 18. The miniature MEMS autofocus cameramodule of claim 1, wherein the miniature MEMS camera module, uponassembly, defines an optical axis that is displaced from an axis of themovable lens group not more than approximately 0.5 mm.
 19. The miniatureMEMS autofocus camera module of claim 1, wherein the miniature MEMScamera module defines an optical axis that is displaced from an axis ofthe movable lens group not more than approximately 0.2 mm.
 20. Theminiature MEMS autofocus camera module of claim 1, wherein the miniatureMEMS camera module, upon assembly, defines an optical axis that isdisplaced from an axis of the movable lens group not more thanapproximately 0.1 mm.
 21. The miniature MEMS autofocus camera module ofclaim 36, wherein the autofocus zoom optical module comprises one ormore pairs of adjacent lens surfaces that include abutting registrationfeatures.
 22. An optical assembly for a miniature MEMS camera modulecomprising: an optical assembly housing configured for coupling with animage sensor component; and an autofocus optical module coupled withinthe housing including a MEMS actuator that is configured to move one ormore movable lenses relative to one or more fixed lenses along anoptical axis to adjust a focusing distance of the autofocus opticalmodule.
 23. The optical assembly of claim 22, wherein the one or moremovable lenses are disposed nearest an object end of the optical pathand are movable along the optical axis.
 24. The optical assembly ofclaim 23, wherein the one or more fixed lenses are disposed nearest animage end of the optical path and are fixed in position relative to thehousing.
 25. The optical assembly of claim 24, wherein the opticalassembly housing is configured to couple with an image sensor componentthat has an image sensor portion that is disposed approximately at aback focal length of the one or more fixed lenses.
 26. The opticalassembly of claim 22, wherein the one or more fixed lenses comprisesfirst and second fixed lens groups each having one or more lenses thatare fixed relative to the housing, wherein the one or more movablelenses are disposed between the first and second fixed lens groups. 27.The optical assembly of claim 22, wherein the optical assembly comprisesone or more pairs of adjacent lens surfaces that include abuttingregistration features.
 28. The optical assembly of claim 22, wherein theoptical assembly, upon assembly with an image sensor component, definesan optical axis that is displaced from an axis of the movable lens groupnot more than approximately 0.5 mm.
 29. The optical assembly of claim22, wherein the optical assembly, upon assembly with an image sensorcomponent, defines an optical axis that is displaced from an axis of themovable lens group not more than approximately 0.2 mm.
 30. The opticalassembly of claim 22, wherein the optical assembly, upon assembly withan image sensor component, defines an optical axis that is displacedfrom an axis of the movable lens group not more than approximately 0.1mm.
 31. The optical assembly of claim 30, wherein the optical assemblycomprises one or more pairs of adjacent lens surfaces that includeabutting registration features.
 32. The optical assembly of claim 22,wherein upon assembly with an image sensor component forms an autofocusmodule whereby a registration of de-center between the one or more fixedlenses and the one or more moving lenses comprises approximately sevenmicrons or less.
 33. The optical assembly of claim 22, wherein uponassembly with an image sensor component forms an autofocus modulewhereby a registration of de-center between the one or more fixed lensesand the one or more moving lenses comprises approximately five micronsor less.
 34. The optical assembly of claim 22, wherein a registration ofde-center between the one or more fixed lenses and the one or moremoving lenses comprises approximately three microns or less.
 35. Theoptical assembly of claim 22, wherein a registration of tilt between theone or more fixed lenses and the one or more moving lenses comprisesapproximately 0.3 microns or less.
 36. The optical assembly of claim 22,wherein a registration of tilt between the one or more fixed lenses andthe one or more moving lenses comprises approximately 0.2 microns orless.
 37. The optical assembly of claim 22, wherein a registration oftilt between the one or more fixed lenses and the one or more movinglenses comprises approximately 0.1 microns or less.